谷歌真是风波不断——近期，MWR实验室的研究人员又发现一个0day漏洞。这个漏洞存在于安卓系统中Google Admin应用程序处理一些URL的方式中，攻击者甚至可以通过这个漏洞绕过沙箱机制。MWR实验室在报告中提到了该漏洞原理：当Google Admin应用程序接收到一个URL，并且该URL是通过同一设备上任何其他应用的IPC调用接收时，Admin程序会将这个URL加载到它活动内的 Webview中。这时若攻击者使用一个file:// URL链接到他们所控制的文件，那么就可以使用符号链接绕过同源策略，并接收到Admin沙箱中的数据。
Sandbox bypass through Google Admin WebView
An issue was found in Google’s Android Admin application that allowed other applications on the device to bypass sandbox restrictions to read arbitrary files through the use of symbolic links.
The advisory can be downloaded here.
An issue was found when the Google Admin application received a URL via an IPC call from any other application on the same device. The Admin application would load this URL in a webview within its own activity. If an attacker used a
file://URL to a file that they controlled, then it is possible to use symbolic links to bypass Same Origin Policy and retrieve data out of the Google Admin sandbox
A malicious application on the same device as the Google Admin application is able to read data out of any file within the Google Admin sandbox, bypassing the Android Sandbox.
The Google Admin application (
com.google.android.apps.enterprise.cpanel), has an exported activity that accepts an extra string called
setup_url. This can be triggered by any application on the device creating a new intent with the
data-uri set to
http://localhost/foo and the
setup_url string set to a file url that they can write to, such as
The ResetPinActivity will then load this in the WebView under the privileges of the Google Admin application.
The attacker adds HTML in to their world readable file, which includes an iframe that will load the world readable file again within the frame after a 1 second delay. The Google Admin application loads this file and renders it into its WebView.
Next the attacker deletes the world readable file and replaces it with a symbolic link of the same name that points to a file in the Google Admin sandbox.
After one second the iframe in the WebView will load the file, which will now point to one of its own files. Because the parent and child frames have the same URL, the Same Origin Policy allows the parent frame to query the contents of the child frame. This means that the HTML that the attacker controls can read from the files loaded into the iframe and extract their data.
Devices with Google Admin installed should not install any untrusted third party applications.
No updated version has been released as of the time of publication
Refer to attached detailed advisory above.
|17/03/2015||Issue disclosed to Google Security team|
|18/03/2015||Issue acknowledged by Google Security team|
|20/05/2015||MWR request update from Google Security team, Google Security team reply asking for 2 weeks to allow for update to be released|
|02/06/2015||MWR request update|
|18/06/2015||Google Security acknowledge they have exceeded their own 90 day deadline and request a delay on releasing details until July|
|05/08/2015||MWR announce to Google intention to disclose issue|